run method

@override Vector4? run(Float32List v, ShaderBindings b, FragmentContext c)

Returns linear RGBA for attachment zero. Null discards the fragment.

Implementation

@override
Vector4? run(Float32List v, ShaderBindings b, FragmentContext c) {
  final s = readSurface(v, b, c);
  if (s == null) return null;
  // No ORM map: a purely diffuse model has no response to metallic or
  // roughness, so sampling it would leave a slot the compiler then drops.
  applyCommonMaps(s, v, b, c);
  final lit = accumulateLights(
    s,
    b,
    c,
    shade: (s, light) => s.albedo,
    shadowed: true,
  ).scaled(s.occlusion);
  final ambient =
      (s.albedo.clone()..multiply(s.ambient + sampleLightmap(v, b, c)))
          .scaled(s.occlusion);
  final total = lit + ambient + s.emissive;
  final debug = writeDebugView(c, v, b, s, total);
  if (debug != null) return debug;
  return writeLit(
    c,
    v,
    b,
    color: total,
    alpha: s.alpha,
    normal: s.normal,
    roughness: s.roughness,
  );
}